1. Field of the Invention
This invention relates to digital processing circuits and, more particularly, to digital processing circuits which can handle data of at least two different formats where one word consists respectively of different numbers of bits.
2. Description of the Prior Art
When recording and reproducing an audio signal such as that of music in the PCM (Pulse Coded Modulation) form using an ordinary home video tape recorder, it is necessary to convert the PCM signal into a signal of a data format conforming to the signal of the standard NTSC television system.
As an example of the PCM modulation, it has been known to sample, for instance, two-channel stereo audio signal at a sampling frequency of about 44 kHz for each of the left and right channels, convert the sampled data into a PCM digital data where one sampled data (i.e., one word) consists of 16 or 14 bits, for instance, and place this PCM digital data in the position of the video signal in the standard television signal.
Since the format where one word consists of 16 bits and the format where one word consists of 14 bits are conceivable, it is desired to provide a processing circuit having the compatibility with respect to both the formats and also with the capability of encoding the sampled analog audio signal into a format where one word (one sampling data) consists of 16 bits and processing the 16-bit words as such or after conversion into 14-bit words.